james



HENRY B. James, OF TRENTQN, New

f WATCH.

Specification of Letters Patentl No. 26,593, dated becenib eia}; 18 59,.

My invention consists in controlling the active length of the pendulous spring or as it is generally termed the hair-spring of.

a watch or other time-keeper governed by a balance, by means of combined laminae of brass and steel or other metals which expand and contract differently with the same changes of temperature, so applied to that end of the said spring whichthas heretofore been fixed, as by their expansion and con traction to 'cause the said spring to be taken up through the curb pins, as it expands with an increased temperature, and to belet out as it contracts with a reduction of temperature.

The invention is capable of being applied in a variety of ways, but I propose generally to coil the combined laminae of metal into a convolute spiral form, and to attach theinner end of the coil firmly to one of the plates which hold the movement, and either to attach the end of the hair-spring to the other end of the coil or to a bar or lever against which that end of the coil acts, in such a manner as to cause the said bar or lever to move with the expansion and contraction of the coil produced by changes of temperature, and so take up or let out the hairspring.

Figure 1 in the accompanying drawing, represents the first mentioned mode of ap plying my invention; and Fig. 2 the other mode.

Similar letters of reference indicate corresponding parts in both figures. y

A, represents the potence plate; a, the balance; C, the cock which receives the outer pivot of the staff of the balance; and b, the hair-spring. The inner end of the coil of the hair-spring in both of these examples of my invention is connected with the staff of the balance in the usual manner, but the outer end or as it is generally termed the spare end, instead of being secured in the usual mannen tofaffixedstud seourediin l the potenceplatdis represented inIiFig;

as being attachedsecurely to a stud ried bythe arm c,wl1ich "s,formed ibyflthe term the 5 comp nsating coil? B.

' extension of the i loliteri extremity I,

D, is the regulator. and furnished with curb pinse, Qtoreceive the can of the hairspringinthelusual manne The compensating coil j E, and its arm c,

are made of a. strip of bi ass and a strip of steel united by soldering, brazing. or, other means, the steel bein igon the outside ofthe 1 coil as shown in the" ralwing by the tinting of the steelblue andtliefbi'ass yellow. :The f y 1 inner extremity of the coilis firmlyjsecured by a screw f, toastudthatis securedfin the potence plateAfjbut the outer extremity 1 and its arm 0, are left perfectlyfree Them,

effect of n increase, of temperature zgto I expander open the coil and raise the armg c, V in an upwarddirectionflfrom thepositionflfj represented in Fig. l, and also to producea fiexure of the arm c, i nasimilardirection,

and so to draw the-.hair-spring.up through! the curb pins. ,6, e, and reduce its 1 length, and thus to compensate for the ex-f I pansion of the spring and balance, andqthe eflect of areductionofi temperature is precisely the reverse. i

The mode of applyingithe invention reprej sented in Fig. 2 ditfersfromthat represented in Fig. l, in having the outerior sparefendofn l the coil attachedbythestud a, tooneend of a bar Z, whoseotheraend is secured by a;

screw is, to a small placer, that is secured by a screwy, to the potence plate lApandf in having a compensating coil B, applied so that its outer extremity presses against 1 ,1

the bar Z.

This compensatingcoil isflikey I that represented in Figjigl, except thatitsf outer extremity is not continued to sogreatw extremity of the said coil'is securedjlfirmly said bar Z, must bemadeffsufficientlyelastic.

a length in the form of an arm. HTheinnjer 1 by a screw f, to a stud the plate FL The 1 to keep bearing upon thecompensatingfcoil,

notwithstanding the expansion and contrac-. tion of the latter. The ettect of the expan sion ofthe compensatingcoil is to move the bar Z, upward from the position shown in Fig. 2, and make. it takequp the hai ri g through the curb pins e, andlthe contriacw tion of the said coil permits :the bar 1,; w l

spring in the opposite direction to let on he;

hair-spring. 

